» Articles » PMID: 39473385

Probing Electrostatic and Hydrophobic Associative Interactions in Cells

Overview
Journal J Phys Chem B
Specialty Chemistry
Date 2024 Oct 30
PMID 39473385
Authors
Affiliations
Soon will be listed here.
Abstract

Weak nonspecific interactions between biomacromolecules determine the cytoplasmic organization. Despite their importance, it is challenging to determine these interactions in the intracellular dense and heterogeneous mixture of biomacromolecules. Here, we develop a method to indicate electrostatic and hydrophobic associative interactions and map these interactions. The method relies on a genetically encoded probe containing a sensing peptide and a circularly permuted green fluorescent protein that provides a ratiometric readout. Inside bacterial and mammalian cells, we see that the cytoplasmic components interact strongly with cationic and hydrophobic probes but not with neutral hydrophilic probes, which remain inert. The cytoplasm interacts strongly with highly negatively charged hydrophilic probes, but the HEK293T cytoplasm does not. These associative interactions are modulated by ATP depletion. Hence, the nonspecific associative interaction profile in cells is condition- and species-dependent.

References
1.
Xie Y, Gresham D, Holt L . Increased mesoscale diffusivity in response to acute glucose starvation. MicroPubl Biol. 2023; 2023. PMC: 9996311. DOI: 10.17912/micropub.biology.000729. View

2.
Monteith W, Cohen R, Smith A, Guzman-Cisneros E, Pielak G . Quinary structure modulates protein stability in cells. Proc Natl Acad Sci U S A. 2015; 112(6):1739-42. PMC: 4330749. DOI: 10.1073/pnas.1417415112. View

3.
Depaoli M, Karsten F, Madreiter-Sokolowski C, Klec C, Gottschalk B, Bischof H . Real-Time Imaging of Mitochondrial ATP Dynamics Reveals the Metabolic Setting of Single Cells. Cell Rep. 2018; 25(2):501-512.e3. PMC: 6456002. DOI: 10.1016/j.celrep.2018.09.027. View

4.
Zimmerman S, Trach S . Estimation of macromolecule concentrations and excluded volume effects for the cytoplasm of Escherichia coli. J Mol Biol. 1991; 222(3):599-620. DOI: 10.1016/0022-2836(91)90499-v. View

5.
Gnutt D, Timr S, Ahlers J, Konig B, Manderfeld E, Heyden M . Stability Effect of Quinary Interactions Reversed by Single Point Mutations. J Am Chem Soc. 2019; 141(11):4660-4669. DOI: 10.1021/jacs.8b13025. View